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Many-worlds isn't really a silly concept. It's one of several interpretations that are equally consistent with current experimental results, and it does have ni

Many-worlds isn't really a silly concept. It's one of several interpretations that are equally consistent with current experimental results, and it does have nice properties such as avoiding nondeterminism and nonlocality. It's also (in a way) a conceptually simpler theory, in that many-worlds is roughly what you'd have if you got rid of wave function collapse and naively applied the rest of quantum mechanics. If memory serves me, a substantial percentage of physicists consider many-worlds to be plausible, or even likely. Also, be careful when talking about "observation having a bearing on reality"--the quantum mechanical sense of "observing" state has little to do with the conventional meaning of the word, and absolutely nothing to do with the presence of a conscious observer. On the other hand, an "observer" in the anthropic sense, in the quantum suicide experiment, is generally assumed to be a conscious being (though this isn't strictly required).

Eliezer 17y ago
http://lesswrong.com/lw/q8/many_worlds_one_best_guess/ http://lesswrong.com/lw/q8/many_worlds_one_best_guess/ tl;dr: http://lesswrong.com/lw/q7/if_manyworlds_had_come_first/ http://lesswrong.com/lw/q7/if_manyworlds_had_come_first/
jeromec 17y ago
many-worlds is roughly what you'd have if you got rid of wave function collapse and naively applied the rest of quantum mechanics Okay, but that suggests wave function collapse is erroneous whereas many-worlds is more likely. Based on that alone you can see why I'd consider many-worlds silly. Also, I'd say anyone entertaining it as plausible or even likely is probably reasoning from a purely mathematical vantage point, which is simply not accurate enough to draw such conclusions from. I can't see how else they'd arrive at its feasibility. I don't believe Shrodinger or Einstein would ever propose it. Also, be careful when talking about "observation having a bearing on reality"--the quantum mechanical sense of "observing" state has little to do with the conventional meaning of the word, and absolutely nothing to do with the presence of a conscious observer Hmm, here I won't argue directly against that statement, but instead offer this: If a tree falls in the forest when no one is around does it make a sound? I'm pretty sure you know the answer is 'No', and that's more of where my conscious observation of reality statement came from.
- camccann 17y ago
  Okay, but that suggests wave function collapse is erroneous whereas many-worlds is more likely. Based on that alone you can see why I'd consider many-worlds silly. Also, I'd say anyone entertaining it as plausible or even likely is probably reasoning from a purely mathematical vantage point, which is simply not accurate enough to draw such conclusions from. I can't see how else they'd arrive at its feasibility. I don't believe Shrodinger or Einstein would ever propose it. Wave function collapse wouldn't be so much erroneous as an illusion; it would still describe the way in which other quantum states would decohere and become inaccessible from the perspective of an observer. Remember, these interpretations are equally supported by experiment at this point. Far from being silly, that's exactly why many physicists consider many-worlds to be more likely--wave function collapse seems to be an unnecessary addition that complicates the theory for no benefit (see also: Occam's Razor). Furthermore, reasoning from a purely mathematical perspective is generally better, in this case. Our intuitions about reality are so shaped by the size and energy levels we experience that thinking about quantum mechanical or relativistic phenomena in terms of "physical reality" instead of mathematical structure is likely to lead to misunderstandings and mistakes. Some physicists would argue, actually, that wave function collapse is exactly that sort of mistake. There are a few well-known physicists in favor of many-worlds--Hawking and Feynman, for instance, the latter of whom won a Nobel Prize for his work relating to quantum mechanics. As for Einstein, you may recall his unhappiness at quantum mechanics being nonlocal ("spooky action at a distance") and nondeterministic ("god playing dice with the universe")--whereas the many-worlds interpretation restores both locality and determinism. In the end, I'm no expert, and can't really make any statements about what is or isn't likely, but calling many-worlds "silly" is almost certainly incorrect. It's no sillier than quantum mechanics as a whole. Hmm, here I won't argue directly against that statement, but instead offer this: If a tree falls in the forest when no one is around does it make a sound? I'm pretty sure you know the answer is 'No', and that's more of where my conscious observation of reality statement came from. That question depends on the definition of "sound", actually. Does it mean "longitudinal pressure waves in a physical medium" or does it mean "the subjective experience a human has when perceiving pressure waves in air at certain frequencies"? The answer to the question is completely obvious, and different, in both cases.
  - 17y ago

Eliezer 17y ago

http://lesswrong.com/lw/q8/many_worlds_one_best_guess/ http://lesswrong.com/lw/q8/many_worlds_one_best_guess/ tl;dr: http://lesswrong.com/lw/q7/if_manyworlds_had_come_first/ http://lesswrong.com/lw/q7/if_manyworlds_had_come_first/

jeromec 17y ago

many-worlds is roughly what you'd have if you got rid of wave function collapse and naively applied the rest of quantum mechanics Okay, but that suggests wave function collapse is erroneous whereas many-worlds is more likely. Based on that alone you can see why I'd consider many-worlds silly. Also, I'd say anyone entertaining it as plausible or even likely is probably reasoning from a purely mathematical vantage point, which is simply not accurate enough to draw such conclusions from. I can't see how else they'd arrive at its feasibility. I don't believe Shrodinger or Einstein would ever propose it. Also, be careful when talking about "observation having a bearing on reality"--the quantum mechanical sense of "observing" state has little to do with the conventional meaning of the word, and absolutely nothing to do with the presence of a conscious observer Hmm, here I won't argue directly against that statement, but instead offer this: If a tree falls in the forest when no one is around does it make a sound? I'm pretty sure you know the answer is 'No', and that's more of where my conscious observation of reality statement came from.

camccann 17y ago
Okay, but that suggests wave function collapse is erroneous whereas many-worlds is more likely. Based on that alone you can see why I'd consider many-worlds silly. Also, I'd say anyone entertaining it as plausible or even likely is probably reasoning from a purely mathematical vantage point, which is simply not accurate enough to draw such conclusions from. I can't see how else they'd arrive at its feasibility. I don't believe Shrodinger or Einstein would ever propose it. Wave function collapse wouldn't be so much erroneous as an illusion; it would still describe the way in which other quantum states would decohere and become inaccessible from the perspective of an observer. Remember, these interpretations are equally supported by experiment at this point. Far from being silly, that's exactly why many physicists consider many-worlds to be more likely--wave function collapse seems to be an unnecessary addition that complicates the theory for no benefit (see also: Occam's Razor). Furthermore, reasoning from a purely mathematical perspective is generally better, in this case. Our intuitions about reality are so shaped by the size and energy levels we experience that thinking about quantum mechanical or relativistic phenomena in terms of "physical reality" instead of mathematical structure is likely to lead to misunderstandings and mistakes. Some physicists would argue, actually, that wave function collapse is exactly that sort of mistake. There are a few well-known physicists in favor of many-worlds--Hawking and Feynman, for instance, the latter of whom won a Nobel Prize for his work relating to quantum mechanics. As for Einstein, you may recall his unhappiness at quantum mechanics being nonlocal ("spooky action at a distance") and nondeterministic ("god playing dice with the universe")--whereas the many-worlds interpretation restores both locality and determinism. In the end, I'm no expert, and can't really make any statements about what is or isn't likely, but calling many-worlds "silly" is almost certainly incorrect. It's no sillier than quantum mechanics as a whole. Hmm, here I won't argue directly against that statement, but instead offer this: If a tree falls in the forest when no one is around does it make a sound? I'm pretty sure you know the answer is 'No', and that's more of where my conscious observation of reality statement came from. That question depends on the definition of "sound", actually. Does it mean "longitudinal pressure waves in a physical medium" or does it mean "the subjective experience a human has when perceiving pressure waves in air at certain frequencies"? The answer to the question is completely obvious, and different, in both cases.
- 17y ago